Sleek, light and surprisingly warm, the Nano Puff Pullover’s modus operandi is one of versatility. It’s an insulated pullover in spring squalls, a sleek micro-belay parka on chilly rock routes and a thermal midlayer all in one. The Nano blocks wind, sheds snow and traps heat – even when wet – with the best available synthetic insulation: PrimaLoft ONE (60-g) is incredibly warm, low-bulk, compressible and hydrophobic. We’ve improved the fit with more shaping through the torso and waist, and refined the deep-venting half-zip with a soft, wicking interior storm flap and zipper garage. We’ve also moved the women’s style into our classic Nano Puff Pullover's “brick” quilting pattern, with narrow horizontal quilting on the shaped side panels, and burly thread for added durability. The 100% recycled polyester ripstop shell still glides effortlessly, worn as an outer or midlayer. It all packs down to practically nothing and stuffs into a single chest pocket that has a carabiner clip-in loop. Elasticized cuffs and hem seal out wind and trap warmth.

I am 5'5", 34 C chest and the medium was comfortable, if not a bit loose which is exactly what I wanted. I have a short torso which makes this fall to the hip. It packs into the chest pocket into the size of a grapefruit. To hot in Denver to wear right now, but looking forward to using as the temps get cooler. Wish it had side hand pockets.

This pullover is very warm yet is still lightweight. I usually like the feeling of fleece, but this jacket is just as comfortable if not more! It can pack up very small, weighs almost nothing, and keeps you warm and comfortable all day!

I love this pullover--great colors in a technical piece that's attractive enough to wear around town. I wish it were a bit longer in the body but that is my only negative; the hem lifts up a lot when I raise my arms. Other than that though, it's fantastic!

This is a fantastic piece. I ordered the Volcanic Blue. It weighs practically nothing, is great for layering and is SO comfortable. I'd wear it 24/7 if I could! It offers lightweight warmth and allows room for a few light layers underneath too The neck can be zipped all the way without being constrictive and the chest pocket has ample room for cell phones, keys or granola bars. It goes great with a softshell due to the fabric or even under a midweight fleece. And it looks nicer than just wearing a fleece jacket. This is one of the best purchases I have made. I liked it so much I bought another one in the amaranth! Only complaint is no hand pockets those would make it absolutely perfect. Find it on sale and buy it - you will NOT regret it!

I purchased a nano pullover for myself in December 2010. I don't think it has left my body since! I have since got one for both daughters and my wife! This is the answer for everyday wear and layering under ski/snow clothes. A must have for Colorado!